Objective:

The overall purpose of this research is to investigate conditions that enhance the mobility of lead in contaminated soils for in-situ remediation by a pump-and-treat process, or alternatively, to chemically immobilize lead through sorption or precipitation processes. The study will increase our understanding of lead chemistry in soils and groundwaters through both physico-chemical techniques and computer modeling.

Approach:

Although lead is often considered "immobile" in soils, dissolved lead in
groundwater exceeds the EPA drinking water MCL in numerous lead-contaminated
soils. Better understanding is needed of processes that control lead mobility in
soils, including sorption-desorption, precipitation-dissolution, and
complexation; and the effects on these processes of environmental conditions
such as pH, soil organic matter content, metal speciation, surface chemical
properties of soil mineral phases, and reaction time (kinetics).

Oxides of iron are ubiquitous subsurface mineral constituents and control the
mobility of metal ions in soils and groundwater by adsorptive retardation. In
this laboratory study, iron-oxide-coated sand (IOCS) is used to model lead
chemical behavior in soil using batch and column reactor experiments. Several
parameters are varied in order to ascertain their effects: pH, ionic strength,
complexation by organic ligands, competing cations, and reaction time. Batch
reactor experiments are used to study sorption and desorption kinetics and to
determine equilibrium parameters for lead adsorption. Continuous-flow
packed-beds (soil columns) are used to more closely simulate field conditions of
porous media flow. Data from both batch and soil column studies is used in
computer modeling to simulate the effects of changing environmental conditions
on lead mobility.

Progress and Final Reports:

Main Center Abstract and Reports:

Subprojects under this Center:(EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).R825689C001 Interactions between Electron Acceptors in the Treatment
of Wastewaters Containing Sulfate, Chlorophenols and AcetateR825689C002 Enhancing Biodegradation with Sorption and Alternating
Aerobic/Anaerobic EnvironmentsR825689C003 Development and Verification of a Numerical Model to Predict
the Fate and Transport of Chlorinated Phenols in GroundwaterR825689C004 Redox Transformations of Inorganic Pollutants: Coupling
to the Biogeochemical MatrixR825689C005 Hexavalent Chromium Sorption and Desorption in Natural
Soils and SubsoilsR825689C006 Biotransformation of Ordnance Wastes Using Unique Consortia
of Anaerobic BacteriaR825689C007 The Effect of Environmental Conditions on Reductive Dechlorination
RatesR825689C008 Lead Sorption, Transport, and Remediation in Natural Soils
and SubsoilsR825689C009 Degradation of Chlorinated Aliphatic Compounds by Nitrifying
BacteriaR825689C010 Remediation of Contaminated Soil from the Baldock Station
Maintenance FacilityR825689C011 The Effect of Apparent EH, Compound Structure, and Electron
Donor on Anaerobic Biotransformation of Trinitrotoluene and its MetabolitesR825689C012 The "Bubble Wall": A Passive In Situ System
for Treatment and/or Containment of Contaminated GroundwaterR825689C013 Inhibition, Inactivation and Recovery: A Universal Model
for Aerobic Cometabolic Degradation of Aliphatic CompoundsR825689C014 Development, Characterization, and Performance Evaluation
of Ferrous-Ferric Oxide Adsorbents for Metal Removal from Contaminated GroundwaterR825689C015 Redox Transformations of Organic and Inorganic Contaminants
in the Subsurface EnvironmentR825689C016 Demonstration of a Permeable Barrier Technology for the
Bioremediation of Ground Water Contaminated with Waste MixturesR825689C017 Development of a Vitamin B12-Amended Bioremediation Process
for the Reductive Dechlorination of Chlorobiphenyls at all Chlorine PositionsR825689C018 An Investigation of the Chlorinated Hydrocarbon Substrate
Range of the Filamentous Fungus, Graphium sp.R825689C019 Aerobic Cometabolism of Chloroform, 1,1,1-trichloroethane,
1,1-dichloroethylene, and Other Chlorinated Aliphatic Hydrocarbons by Microbes
Grown on Butane and PropaneR825689C020 Cytochrome P-450: An Emerging Catalyst for the Cometabolism
of Chlorinated Aliphatic Hydrocarbons and Methyl tert-butyl Ether?R825689C021 In-Situ Measurement of TCE Degradation Using a Single-Well
"Push-Pull" TestR825689C022 Development and Characterization of Redox Sensors for
Environmental MonitoringR825689C023 Assessing Metal Speciation in the Subsurface EnvironmentR825689C024 Simultaneous Removal of the Adsorbable and Electroactive
Metals from Contaminated Soils and GroundwaterR825689C025 Multisolute Sorption and Transport Model for Copper, Chromium,
and Arsenic Sorption on an Iron-Coated Sand, Synthetic Groundwater SystemR825689C026 Development of Alkoxysilanes as Slow Release Substrates
for the Anaerobic/Aerobic Transformation of Chlorinated SolventsR825689C027 Aerobic Cometabolism of Chlorinated Aliphatic Hydrocarbons
by Toluene-Oxidizing BacteriaR825689C028 Development and Characterization of Sensors and Field
Instrumentation for Monitoring of Environmental Redox ConditionsR825689C029 Aerobic Cometabolism of Methyl tert-butyl Ether by Microorganisms
Grown on Aliphatic HydrocarbonsR825689C030 Biotransformation of Lead and Chromate by BacteriaR825689C031 Magnetic Resonance Studies of Heavy Metals in Clays, Zeolites
and CeramicsR825689C032 Probing the Redox Properties of Environmental Systems: Natural Phenolic MaterialsR825689C033 Reductive Dehalogenation at Carbon and Derivatized Carbon
ElectrodesR825689C034 Detection of Microorganisms Capable of Anaerobic Degradation
of Hazardous Substances in Natural EnvironmentsR825689C035 Treatment of Complex MixturesR825689C036 Oxidation of Chlorinated Solvents by MethanotrophsR825689C037 Detection and Assessment of Subsurface ContaminationR825689C038 Design of Reliable and Cost-Effective Mitigation SchemesR825689C039 Gaseous Stripping of Nonaqueous Phase Liquids from the
Vadose ZoneR825689C040 Anaerobic Microbial Transformation of Homocyclic and Heterocyclic Polynuclear Aromatic HydrocarbonsR825689C041 Effects of Sorption on Biodegradation of Halogenated OrganicsR825689C042 Trace Metal Removal ProcessesR825689C043 FASTCHEM Applications and Sensitivity AnalysisR825689C044 Long-term Chemical Transformation of 1,1,1-Trichloroethane
(TCA) and Freon 113 under Aquifer ConditionsR825689C045 In-Situ Anaerobic Biological Treatment of Aromatics in
GroundwaterR825689C046 Use of Starvation and Stress Promoters for Biodegradation
of Hazardous WastesR825689C047 Determining and Modeling Diffusion-Limited Sorption and
Desorption Rates of Organic Contaminants in Heterogeneous SoilsR825689C048 Dispersion Modeling of Volatile Organic Emissions from
Ground-Level Treatment SystemsR825689C049 Subsurface Mixing of Nutrients and Groundwater for in-Situ
BioremediationR825689C050 Test-Bed Evaluation of In-Situ Bioremediation of Chlorinated
Aliphatic Compounds by Toluene Oxygenase MicroorganismsR825689C051 Demonstration of in-Situ Bioremediation of Chlorinated
Aliphatics by Methanotrophs at St. JosephR825689C052 Aquifer Remediation Design in the Presence of Kinetic
LimitationsR825689C053 Determination of Macroscopic Transport Parameters for
Biologically Reacting Solutes in AquifersR825689C054 Transformation of Chlorinated Hydrocarbons by Reduced
Metallocoenzymes--Kinetic Model Development and Applications to Environmental
SystemsR825689C055 Microbial Degradation of Toluene Under Sulfate-Reducing
Conditions--The Role of IronR825689C056 Transformation of TCE by Methanotrophic BiofilmsR825689C057 Heavy Metals in Ceramic Matrix: Heavy Metals/Clay Interactions
in Ceramic ProcessingR825689C058 Radon-222 Method for Locating and Quantifying Contamination
by Residual Non-Aqueous Phase Liquids in the SubsurfaceR825689C059 Process Submodel Formulation and Parameter Estimation
for Simulation of BioremediationR825689C060 Enhancement of Biodegradation through the Use of Substituted
Porphyrins to Treat Groundwater Contaminated with Halogenated AliphaticsR825689C061 Field Test of In-Situ Vapor Stripping for Removal of VOCS
from GroundwaterR825689C062 System Design for Enhanced In-Situ Biotransformation of
Carbon Tetrachloride: Application to DOE's Arid Site Integrated DemonstrationR825689C063 Modeling Strategies for Optimizing In-Situ BioremediationR825689C064 Anaerobic Treatment of Chlorinated Solvent Contaminated
GroundwaterR825689C065 In Situ Treatment of Chlorinated SolventsR825689C066 Moffett Field In-Situ Bioremediation Study in Support
of Full Scale ApplicationR825689C067 Full-Scale Evaluation of In Situ Bioremediation of Chlorinated
Solvent Groundwater ContaminationR825689C068 Upscaling Pore-Scale Hydrodynamics and the Transport of
Reactive SolutesR825689C069 Pathways of Anaerobic Toluene Metabolism by a Sulfate-Reducing
Bacterium, Strain PRTOL1R825689C070 Anaerobic Ethylbenzene Oxidation in Denitrifying Strain
EB1R825689C071 Molecular Approaches to Optimize Starvation Promoter Dricen
TCE Bioremediation in PseudomonasR825689C072 Modeling VOC Emissions from Hazardous Waste SitesR825689C073 Reductive Transformation of Chlorinated Hydrocarbons by
Reduced Ethenes Catalyzed by Vitamin B12 - Mechanistic and Kinetic StudiesR825689C074 Evaluation of Strategies for Full Scale Bioremediation
of the Seal Beach Site Using Anaerobic Microbial ProcessesR825689C075 Trace Element Adsorption in Porous Particle Packed BedsR825689C076 Hydrologic and Biological Factors Affecting Aquifer Clogging
During In-Situ BioremediationR825689C077 Full-Scale Evaluation of an Apparatus for Down-well Oxygen
Transfer to Implement In situ Bioremediation at Edwards AFBR825689C078 Field Testing of Palladium-Catalyzed Hydrodehalogenation
for Chlorinated Hydrocarbon Removal from GroundwaterR825689C079 Physics of Dissolution of Nonaqueous Phase Liquids: Pore
Networks and Field SimulationsR825689C080 Three-Phase Flow in Fractured MediaR825689C081 Effects of Redox Zones on the Fate and Transport of Contaminants
in the Saturated Subsurface; Characterization and SimulationR825689C082 Biochemical Mechanisms of PCE Dehalogenation by Strain
MS-1, and its Potential for In-situ BioaugmentationR825689C083 A Large Scale Model for Anaerobic Bioremediation at the
Seal Beach SiteR825689C084 Mechanisms, Chemistry, and Kinetics of Anaerobic Degradation
of cDCE and Vinyl ChlorideR825689C085 Bioenhanced In-Well Vapor Stripping to Treat Trichloroethylene
(TCE)R825689C086 Effect of Chemical Structure on the Biodegradability of
Halogenated Hydro-carbonsR825689C087 Trace Element Adsorption in Porous Particle Packed BedsR825689C088 Arsenic Removal in High Capacity Porous Alumina Packed-Bed
ReactorsR825689C089 Measurement of Interfacial Areas and Mass Transfer Coefficients
Between Residual PCE and Water During Surfactant Enhanced Aquifer RemediationR825689C090 Proof of Gene Expression During BioaugmentationR825689C091 Experimental and Mathematical Study of Biomass Growth
in Pore Networks and its Consequences in BioremediationR825689C092 Gene probes for detecting anaerobic alkylbenzene-degrading
bacteriaR825689C093 Investigation of Palladium Catalyzed Hydrodehalogenation
for the Removal of Chlorinated Groundwater Contaminants: Surface Chemistry of
Catalyst Deactivation and RegenerationR825689C094 Aerobic Methanotrophic Transformation of Biphenyl, Monochlorobiphenyls,
and Dichlorobiphenyls

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.